At the show he introduced one of his songs by describing it as, roughly, "a song about a country which traded freedom for security, and replaced its democratic government with a Christian theocracy." Something like that anyway.
So, Jeffrey Foucault is indeed very shrill and is happy to be shrill in front of an audience.
You can listen to the title track of his new album, Ghost Repeater, here.
Or the song Americans in Corduroys here.